2024-03-21 14:30:48 +08:00

244 lines
7.4 KiB
JavaScript

/******************************************************************************************
* Assume a web server serves up the utf8 encoding of a random Uint8Array,
* so that xhr.responseText is a string corresponding to the in-memory
* representation of the Uint8Array. This test demonstrates a bug in xmlhttprequest-ssl,
* where the utf8 endcoding of a byte with 0x80 <= byte <= 0xff, is torn across 2 chunks.
*
* Consider a code point 0x80. The utf8 encoding has 2 bytes 0xc2 and 0x80.
* It is possible for one chunk to end with 0xc2 and the next chunk starts with 0x80.
* This is what is meant by tearing. The fix is to remove
* self.responseText += data.toString('utf8');
* from the response 'data' handler and add the following to the response 'end' handler
* // Construct responseText from response
* self.responseText = self.response.toString('utf8');
*/
// @ts-check
'use strict';
const assert = require("assert");
const http = require("http");
const useLocalXHR = true;
const XHRModule = useLocalXHR ? "../lib/XMLHttpRequest" : "xmlhttprequest-ssl";
const { XMLHttpRequest } = require(XHRModule);
const supressConsoleOutput = true;
function log (...args) {
if ( !supressConsoleOutput)
console.debug(...args);
}
var serverProcess;
/******************************************************************************************
* This section produces a web server that serves up
* 1) Buffer.from(ta.buffer) using url = "http://localhost:8888/binary";
* 2) utf8 encoding of ta_to_hexStr(ta) using url = "http://localhost:8888/binaryUtf8";
* where ta is a Float32Array.
* Note: In order to repro utf8 tearing ta.length needs to be pretty big
* N = 1 * 1000 * 1000;
*/
/**
* Create a string corresponding to the in-memory representation of Float32Array ta.
*
* @param {Float32Array} ta
* @returns {string}
*/
function ta_to_hexStr(ta) {
const u8 = new Uint8Array(ta.buffer);
return u8.reduce((acc, cur) => acc + String.fromCharCode(cur), "");
}
/**
* Create a random Float32Array of length N.
*
* @param {number} N
* @returns {Float32Array}
*/
function createFloat32Array(N) {
assert(N > 0);
let ta = new Float32Array(N);
for (let k = 0; k < ta.length; k++)
ta[k] = Math.random();
//ta = new Float32Array([1, 5, 6, 7]); // Use to debug
return ta;
}
const N = 1 * 1000 * 1000; // Needs to be big enough to tear a few utf8 sequences.
const f32 = createFloat32Array(N);
/**
* From a Float32Array f32 transform into:
* 1) buffer: Buffer.from(ta.buffer)
* 2) bufferUtf8: utf8 encoding of ta_to_hexStr(ta)
*
* @param {Float32Array} f32
* @returns {{ buffer: Buffer, bufferUtf8: Buffer }}
*/
function createBuffers(f32) {
const buffer = Buffer.from(f32.buffer);
const ss = ta_to_hexStr(f32);
const bufferUtf8 = Buffer.from(ss, 'utf8'); // Encode ss in utf8
return { buffer, bufferUtf8 };
}
const { buffer, bufferUtf8 } = createBuffers(f32);
/**
* Serves up buffer at
* url = "http://localhost:8888/binary";
* Serves up bufferUtf8 at
* url = "http://localhost:8888/binaryUtf8";
*
* @param {Buffer} buffer
* @param {Buffer} bufferUtf8
*/
function createServer(buffer, bufferUtf8) {
serverProcess = http.createServer(function (req, res) {
switch (req.url) {
case "/binary":
return res
.writeHead(200, {"Content-Type": "application/octet-stream"})
.end(buffer);
case "/binaryUtf8":
return res
.writeHead(200, {"Content-Type": "application/octet-stream"})
.end(bufferUtf8);
default:
return res
.writeHead(404, {"Content-Type": "text/plain"})
.end("Not found");
}
}).listen(8888);
process.on("SIGINT", function () {
if (serverProcess)
serverProcess.close();
serverProcess = null;
});
}
createServer(buffer, bufferUtf8);
/******************************************************************************************
* This section tests the above web server and verifies the correct Float32Array can be
* successfully reconstituted for both
* 1) url = "http://localhost:8888/binary";
* 2) url = "http://localhost:8888/binaryUtf8";
*/
/**
* Assumes hexStr is the in-memory representation of a Float32Array.
* Relies on the fact that the char codes in hexStr are all <= 0xFF.
* Returns Float32Array corresponding to hexStr.
*
* @param {string} hexStr
* @returns {Float32Array}
*/
function hexStr_to_ta(hexStr) {
const u8 = new Uint8Array(hexStr.length);
for (let k = 0; k < hexStr.length; k++)
u8[k] = Number(hexStr.charCodeAt(k));
return new Float32Array(u8.buffer);
}
/**
* Verify ta1 and ta2 are the same kind of view.
* Verify the first count elements of ta1 and ta2 are equal.
*
* @param {Float32Array} ta1
* @param {Float32Array} ta2
* @param {number} [count=1000]
* @returns {boolean}
*/
function checkEnough(ta1, ta2, count = 1000) {
assert(ta1 && ta2);
if (ta1.constructor.name !== ta2.constructor.name) return false;
if (ta1.length !== ta2.length) return false;
if (ta1.byteOffset !== ta2.byteOffset) return false;
for (let k = 0; k < Math.min(count, ta1.length); k++) {
if (ta1[k] !== ta2[k]) {
log('checkEnough: Not Equal!', k, ta1[k], ta2[k]);
return false;
}
}
return true;
}
const xhr = new XMLHttpRequest();
const url = "http://localhost:8888/binary";
const urlUtf8 = "http://localhost:8888/binaryUtf8";
/**
* Send a GET request to the server.
* When isUtf8 is true, assume that xhr.response is already
* utf8 encoded so that xhr.responseText.
*
* @param {string} url
* @param {boolean} isUtf8
* @returns {Promise<Float32Array>}
*/
function Get(url, isUtf8) {
return new Promise((resolve, reject) => {
xhr.open("GET", url, true);
xhr.onloadend = function(event) {
log('xhr.status:', xhr.status);
if (xhr.status >= 200 && xhr.status < 300) {
const contentType = xhr.getResponseHeader('content-type');
assert.equal(contentType, 'application/octet-stream');
const dataTxt = xhr.responseText;
const data = xhr.response;
assert(dataTxt && data);
log('XHR GET:', contentType, dataTxt.length, data.length, data.toString('utf8').length);
log('XHR GET:', data.constructor.name, dataTxt.constructor.name);
if (isUtf8 && dataTxt.length !== data.toString('utf8').length)
throw new Error("xhr.responseText !== xhr.response.toString('utf8')");
const ta = isUtf8 ? new Float32Array(hexStr_to_ta(dataTxt)) : new Float32Array(data.buffer);
log('XHR GET:', ta.constructor.name, ta.length, ta[0], ta[1]);
if (!checkEnough(ta, f32))
throw new Error("Unable to correctly reconstitute Float32Array");
resolve(ta);
}
reject(new Error(`Request failed: xhr.status ${xhr.status}`));
}
xhr.send();
});
}
/**
* Test function which gets utf8 encoded bytes of the typed array
* new Uint8Array(new Float32Array(N).buffer),
* then it gets the raw bytes from
* new Uint8Array(new Float32Array(N).buffer).
* Before the utf8 tearing bug is fixed,
* Get(urlUtf8, true)
* will fail with the exception:
* Error: xhr.responseText !== xhr.response.toString('utf8').
*
* @returns {Promise<Float32Array>}
*/
function runTest() {
return Get(urlUtf8, true)
.then(() => { return Get(url, false); });
}
/**
* Run the test.
*/
setTimeout(function () {
runTest()
.then((ta) => { console.log("done", ta?.length); })
.finally(() => {
if (serverProcess)
serverProcess.close();
serverProcess = null;
});
}, 100);